Casino giant MGM is asking Massachusetts gambling regulators to slow down the process of collecting required state fees for a casino license in the state's western region as it seeks to open an $800 million casino in downtown Springfield.

MGM Springfield President Michael Mathis suggested Thursday that the state Gaming Commission award the company a license, as expected, by the end of May.

But he requested the commission consider holding off finalizing the process and collecting the required state fees, pending the outcome of an effort by gambling opponents to repeal the state's 2011 casino law.

The proposed anti-casino ballot question is currently before the state's highest court.

Repeal the Casino Deal, the group that is pushing for the referendum, said MGM's request is a sign the "landscape for casinos has shifted" in Massachusetts.